For this type of method for searching an approach for improving a steam-using facility, as one conventional example, there can be mentioned a method in which the facility improving approach includes replacing or repairing a steam trap, including steps of: diagnosing a present steam trap provided in the steam-using facility; based on a diagnosis result, computing a trap-passed steam loss amount for the entire steam-using facility due to trap defect or the like, by means of arithmetic addition; computing a possible reduction amount in the trap-passed steam loss amount that would be obtained by implementing the facility improving approach, by means of arithmetic addition; computing a predicted total steam supply amount after implementation of the improving approach by subtracting the reduction amount in the trap-passed steam loss amount from a present total steam supply amount of the steam-using facility; and determining whether or not the facility improving approach is appropriate, based on a magnitude of the predicted total steam supply amount after implementation of the improving approach (see Patent Document 1 below).    Patent Document 1: Japanese Unexamined Patent Application No. 2005-114366A